GtkSpinButton: don't constantly recreate style contexts for buttons

Cache the style contexts for the up and down panels, instead of recreating
them each time they are drawn or size requested. GtkSpinButtons were
many times slower to draw than other widgets because of the constant
style matching.

https://bugzilla.gnome.org/show_bug.cgi?id=698682

1 files changed, 48 insertions, 10 deletions

diff --git a/gtk/gtkspinbutton.c b/gtk/gtkspinbutton.c
index 0928d9ea60..0f97078024 100644
--- a/gtk/gtkspinbutton.c
+++ b/gtk/gtkspinbutton.c
@@ -156,6 +156,9 @@ struct _GtkSpinButtonPrivate
   GdkWindow     *down_panel;
   GdkWindow     *up_panel;
 
+  GtkStyleContext *down_panel_context;
+  GtkStyleContext *up_panel_context;
+
   GdkWindow     *click_child;
   GdkWindow     *in_child;
 
@@ -248,6 +251,7 @@ static void gtk_spin_button_grab_notify    (GtkWidget          *widget,
                                             gboolean            was_grabbed);
 static void gtk_spin_button_state_flags_changed  (GtkWidget     *widget,
                                                   GtkStateFlags  previous_state);
+static void gtk_spin_button_style_updated   (GtkWidget         *widget);
 static gboolean gtk_spin_button_timer          (GtkSpinButton      *spin_button);
 static gboolean gtk_spin_button_stop_spinning  (GtkSpinButton      *spin);
 static void gtk_spin_button_value_changed  (GtkAdjustment      *adjustment,
@@ -328,6 +332,7 @@ gtk_spin_button_class_init (GtkSpinButtonClass *class)
   widget_class->focus_out_event = gtk_spin_button_focus_out;
   widget_class->grab_notify = gtk_spin_button_grab_notify;
   widget_class->state_flags_changed = gtk_spin_button_state_flags_changed;
+  widget_class->style_updated = gtk_spin_button_style_updated;
 
   entry_class->activate = gtk_spin_button_activate;
   entry_class->get_text_area_size = gtk_spin_button_get_text_area_size;
@@ -684,7 +689,16 @@ gtk_spin_button_init (GtkSpinButton *spin_button)
 static void
 gtk_spin_button_finalize (GObject *object)
 {
-  gtk_spin_button_set_adjustment (GTK_SPIN_BUTTON (object), NULL);
+  GtkSpinButton *spin_button = GTK_SPIN_BUTTON (object);
+  GtkSpinButtonPrivate *priv = spin_button->priv;
+
+  gtk_spin_button_set_adjustment (spin_button, NULL);
+
+  if (priv->down_panel_context)
+    g_object_unref (priv->down_panel_context);
+
+  if (priv->up_panel_context)
+    g_object_unref (priv->up_panel_context);
 
   G_OBJECT_CLASS (gtk_spin_button_parent_class)->finalize (object);
 }
@@ -730,7 +744,7 @@ gtk_spin_button_unmap (GtkWidget *widget)
 static void
 gtk_spin_button_panel_nthchildize_context (GtkSpinButton *spin_button,
                                            GtkStyleContext *context,
-                                           GdkWindow *panel)
+                                           gboolean         is_down_panel)
 {
   GtkSpinButtonPrivate *priv = spin_button->priv;
   GtkWidget *widget = GTK_WIDGET (spin_button);
@@ -777,7 +791,7 @@ gtk_spin_button_panel_nthchildize_context (GtkSpinButton *spin_button,
   gtk_widget_path_iter_add_class (siblings_path, up_pos, GTK_STYLE_CLASS_SPINBUTTON);
   gtk_widget_path_iter_add_class (siblings_path, down_pos, GTK_STYLE_CLASS_SPINBUTTON);
 
-  if (panel == priv->down_panel)
+  if (is_down_panel)
     gtk_widget_path_append_with_siblings (path, siblings_path, down_pos);
   else
     gtk_widget_path_append_with_siblings (path, siblings_path, up_pos);
@@ -846,12 +860,20 @@ static GtkStyleContext *
 gtk_spin_button_panel_get_context (GtkSpinButton *spin_button,
                                    GdkWindow *panel)
 {
-  GtkStyleContext *context;
+  GtkSpinButtonPrivate *priv = spin_button->priv;
+  GtkStyleContext **contextp;
 
-  context = gtk_style_context_new ();
-  gtk_spin_button_panel_nthchildize_context (spin_button, context, panel);
+  contextp = (panel == priv->down_panel) ?
+    &priv->down_panel_context : &priv->up_panel_context;
+
+  if (*contextp == NULL)
+    {
+      *contextp = gtk_style_context_new ();
+      gtk_spin_button_panel_nthchildize_context (spin_button, *contextp,
+                                                 panel == priv->down_panel);
+    }
 
-  return context;
+  return *contextp;
 }
 
 static void
@@ -874,8 +896,6 @@ gtk_spin_button_panel_get_size (GtkSpinButton *spin_button,
   gtk_style_context_get_padding (context, state, &button_padding);
   gtk_style_context_get_border (context, state, &button_border);
 
-  g_object_unref (context);
-
   if (width)
     *width = icon_size + button_padding.left + button_padding.right +
              button_border.left + button_border.right;
@@ -1004,7 +1024,6 @@ gtk_spin_button_panel_draw (GtkSpinButton   *spin_button,
   cairo_restore (cr);
 
   g_object_unref (icon_helper);
-  g_object_unref (context);
 }
 
 static void
@@ -1361,6 +1380,25 @@ gtk_spin_button_state_flags_changed (GtkWidget     *widget,
     }
 }
 
+static void
+gtk_spin_button_style_updated (GtkWidget *widget)
+{
+  GtkSpinButton *spin = GTK_SPIN_BUTTON (widget);
+  GtkSpinButtonPrivate *priv = spin->priv;
+
+  if (priv->down_panel_context)
+    gtk_spin_button_panel_nthchildize_context (spin,
+                                               priv->down_panel_context,
+                                               TRUE);
+
+  if (priv->up_panel_context)
+    gtk_spin_button_panel_nthchildize_context (spin,
+                                               priv->up_panel_context,
+                                               FALSE);
+
+  GTK_WIDGET_CLASS (gtk_spin_button_parent_class)->style_updated (widget);
+}
+
 static gint
 gtk_spin_button_scroll (GtkWidget      *widget,
                         GdkEventScroll *event)